Trials-Based Cardiac Best Practices Stand Test of Time

High-level treatment recommendations published by the American College of Cardiology and the American Heart Association, which were supported by multiple randomized controlled trials, have proved to be the most durable and least likely to change over time.

In a study published in JAMA, Penn Medicine researchers analyzed changes over time in more than 600 Class I ACC/AHA recommendations, each of which recommended strongly in favor of a particular treatment or procedure related to cardiovascular disease.

Based on comparisons of serial editions of ACC/AHA guidelines, the authors observed that four out of five Class I recommendations remained valid across two guideline editions. However, they also noted that one out of every five Class I recommendations was either downgraded to a less certain status, reversed so as to recommend against a previously endorsed treatment, or omitted entirely.

Study leader Mark D. Neuman, M.D., and colleagues also found the odds of a downgrade, reversal, or omission to be more than three times greater among recommendations based on retrospective studies, case reports, or expert opinion versus randomized controlled trials.

While the study was not designed to examine the specific reasons that the individual recommendations were downgraded, supplemental analyses suggested that it was uncommon for recommendations to be downgraded as a result of the emergence of new research studies. Instead, Neuman and colleagues found that many of the downgrades in recommendations they observed may have come from changes over time in how expert physicians interpreted existing medical research.